Recently besieged by steep rate increases for health insurance and homeowner’s insurance, South Florida residents are getting zonked again this year with unexpectedly high auto insurance price hikes.

Rates are higher across the nation, up an average 8.5 percent over the year ending January 2018 and 7.5 percent the previous year, according to statistics from the U.S. Department of Labor. That’s especially bad news for South Florida drivers, who are already paying among the highest rates in the nation.

People with clean driving records — meaning no tickets, no crashes, no insurance claims — are getting renewal notices with premium increases between $200 and $800 — “almost double in some cases,” said Corey Broder, a service agent at Seeman Holtz Property & Casualty Inc. The company, headquartered in Boca Raton, has about 77,000 clients in 11 states, Broder said.

Young adults and drivers with less-than-perfect records can expect to take the worst hits. One client, a single mom who bought her 19-year-old son a used car, recently saw her premium for a six-month term jump by $800 to $2,616, Broder said.

Experts are blaming the rate hikes on increased risks on the roads: Too many drivers are staring at their smartphones from behind the wheel. Cheap gas is causing us to log more miles, and the strong economy is putting more vehicles on the roads.

More crashes lead to more claims. More claims lead to higher costs for insurers. Higher costs for insurers must be recouped by charging everyone more.

In metro regions like South Florida, “high density development is putting more cars on the road, increasing likelihood of accidents,” saidLynne McChristian, Florida representative for the Insurance Information Institute, an industry trade group. “And distracted driving is a huge problem coast to coast.”

Statewide, the number of motor vehicle crashes increased 15 percent between 2014 and 2016, more than three times as fast as the state’s population rate grew during that time, according to data from the Florida Department of Highway Safety and Motor Vehicles. Crashes with fatalities increased 27 percent — from 2,494 to 3,176.

Crashes and fatalities in the tricounty region increased at a slightly lower rate over the same period — crashes increased 12 percent and fatalities jumped 24 percent.

After hovering around 250,000 since 1997, the annual number of crashes statewide began trending upward in 2011, coinciding with the beginning of the economic recovery and the rise in popularity of smartphones. Crashes have increased each year since — from 227,998 in 2011 to 395,785 in 2016, state data shows.

The sharpest price increases are coming from a handful of companies, Broder said, including Safeco Insurance, Nationwide Insurance and Hartford Insurance Company of the Southeast.

According to rate filings with the Florida Office of Insurance Regulation, Safeco, a Liberty Mutual company, hiked its rates for Florida drivers an average of 12.2 percent. That took effect Oct. 14 for new customers and Dec. 20 for renewing customers.

Nationwide received approval for an average 8.2 rate increase that took effect Feb. 15. Hartford Insurance Company of the Southeast is seeking a 7 percent rate increase that would take effect April 21. It would follow a 15.9 percent hike in 2017 and an 18.5 percent increase the year before that.

Three Florida cities were among the 10 most expensive large cities for auto insurance in the United States in 2017, according to a new report by The Zebra, a price comparison website founded in 2012. Hialeah, in Miami-Dade County, was the third most expensive with an average annual premium of $2,709 for a single driver. Miami was fourth at $2,651 and Tampa was eighth at $2,553.

The two most expensive cities were Detroit, Mich. ($5,414), and New Orleans, La. ($3,433).

Florida’s average premium of $1,878 was fifth-largest in the United States, following Michigan, Louisiana, Kentucky and Rhode Island. North Carolina was lowest at $865.

The national average of $1,427 increased about 20 percent since 2011, the report said.

Rates can also be affected by high numbers of claims after catastrophic weather events, and 2017 saw plenty, the report said. The year started with hail in Colorado and tornadoes in the midwest and ended with hurricanes Harvey, Irma and Maria, and California wildfires.

Drivers in states with heavy losses from those weather events won’t start to see effects on rates for several months up to a year afterward, the report said.

Of all those events, Florida was impacted most by Hurricane Irma. But McChristian said losses from hurricanes would have a minimal effect on auto insurance rates compared with what widespread wind damages will do to homeowner insurance rates.

Nicole Beck, spokeswoman for The Zebra, countered that hurricane-related losses inevitably work their way into insurers’ rates: “Irma will most certainly affect rates in 2018,” she said by email. “We do not have data nor can we provide anything more than speculation, but whenever disasters like that hit an area, it results in enormous losses for the carriers, and so to survive they have to raise rates.”

South Florida’s high rates are driven by congestion and fraud, said Adam Lyons, founder and executive chairman at The Zebra. “South Florida is more populous than central and northern Florida. This congestion leads to higher amounts of accidents and vehicle damage, therefore leading to more claims and then higher premiums,” he said.

Of the 50 most expensive of Florida’s 616 cities and census-designated places, 44 are in the tricounty region, according to data provided by The Zebra. The other six are in Hillsborough County, where, according to McChristian, an increase in deaths near U.S. 19 has driven rates higher for people who live near that highway.

Broder said many of his sticker-shocked South Florida customers are responding to price increases by shopping around. Money-saving options include companies that encourage customers to buy their own policies online, including Geico, Progressive and esurance.com (an Allstate company). These companies have rapidly increased market by passing along savings from cutting agents out of the transaction.

“We are seeing the trend to direct [policy writing],” he said, “which is unfortunate for us as an agency, but by going online, companies can cut out the commission, cut out the middleman.”